Deborah of Life in the Fast Lane wrote a neat mega-post about 45 of the world's most amazing artificial islands (both real islands and those in planning stages). Take for example, the Federation Island modeled above:

Federation Island is an artificial island archipelago that will be located off the coast of Sochi in the Black Sea — a complex that will be built in the shape of Russia. Russian developers outlined plans for the $6.2 billion 350-hectare artificial island to be built near the future 2014 Winter Olympic venue in Sochi, to be completed in time for the events.

The floating ‘mini-Russia’ will boast artificial rivers made to mimic the continent’s real waterways, part of a larger effort by the Russian state to revamp the area’s Soviet-era infrastructure before the big event.

The island is expected to house around 25,000 people in apartments and villas, hotels, restaurants, malls, year-round yacht parking, various sea attractions - aquarium, oceanarium, and many other features.